Home Brewing Calculators

A variety of online homebrew calculators is available on the Internet.
Some of the most popular (and generally considered the best) ones are
listed below.

Brewer's Friend

The Brewers Friend website contains a lot of background information on
home brewing, especially on recipe formulation, and has an impressive
array of very good online calculators available to, among other things,
determine alcohol strength, hydrometer temperature corrections, bitterness,
colour, water chemistry and what not. A full online recipe builder
package lets you design your recipes from scratch.
URL: https://www.brewersfriend.com/stats/